1. Field of the Invention
The present invention generally relates to wireless communication networks and more specifically to determining location of devices within the network.
2. Related Art
A typical wireless network includes a number of wireless nodes, such as switches and routers, and a number of client devices. Many client devices are mobile and can move about as they interact over the network. Because of the mobility of the client device, the physical location of the device is uncertain.
Recently, there have been many applications developed that take advantage of knowing the location of a client. These applications are sometime referred to as location based services (“LBS”). Examples of LBS include providing a client information based upon the client's location, such as providing driving directions from a clients present location to a desired destination.
Other location based applications include the area of public safety. One such safety application is E911, which is an enhanced emergency public safety program. In E911, cellular service providers are working with government agencies to provide the location of a cellular phone when it is used to dial 911.
In addition to cellular based systems, location applications can also be advantageous for wireless networks. For example, it is common for employees to take their laptop computers with them as they move about their office, for example, when attending a meeting on another floor of the office building. The laptops can access the company's network via a wireless connection. It would be desirable to be able to determine the location of the laptop, for example, in the case of an emergency this would provide information about the location of the employees.
While some location applications for mobile devices may be provided by cellular carriers, many wireless networks do not have access to a cellular system. In many wireless networks, the mobile devices are adapted to communicate with a local area network and not with a cellular network. In this situation, solutions developed for a cellular network will not support locating devices within the local area network.
Therefore, there is a need for a system and method that overcomes problems associated with determining the location of devices within a wireless network.